Procédé de fabrication de formes d'impression planographique

2-stearoylamino-5-mercapto-1, 3, 4-thiodiazole is prepared by action of stearyl chloride on the corresponding 2-amino derivative in pyridine. Dithiocarbazinic acid stearyl ester is prepared by heating the ammonium salt of dithiocarbazinic acid with octadecyl bromide in alkaline aqueous alcoholic solution. N1[N3-octadecyl-semicarbazide]dithiocarboxylic acid methyl ester is prepared by treating dithiocarbazinic acid methyl ester with stearyl isocyanate in dioxane. 5-heptadecyl-7-hydroxy-2, 3, 4-triazaindolizine is prepared by refluxing 2-amino-1, 3, 4-triazole with stearoyl acetic acid ethyl ester in glacial acetic acid. 1-amino-2-mercapto-5-hydroxyl-1, 3, 4-triazole is prepared by heating carbohydrazide with carbon disulphide in aqueous ammoniacal dioxane, cooling, refluxing the resulting precipitate with aqueous sodium hydroxide and acidifying with hydrochloric acid. This triazole may be alkylated with octyl bromide to form 1-amino-2-octylmercapto-5-hydroxy-1, 3, 4-triazole and treated with ethanolic bromoacetophenone to form 1, 2-2, 3-(5-phenyl-1, 3, 4-thiodiazino)-5-hydroxyl-1, 3, 4-triazole. Specifications 747,048 and 760,181 are referred to.